Tumor Energy Source Depends on Oxygenation Level
Protein responsible for balance may be a cancer drug target
FRIDAY, Nov. 21 (HealthDay News) -- Oxygen-poor areas of tumors use glucose as an energy source, while oxygen-rich areas use lactic acid produced by the oxygen-poor areas, and the protein responsible for this balance may be a good target for cancer drugs, according to research published online Nov. 20 in the Journal of Clinical Investigation.
Pierre Sonveaux, Ph.D., from Universite Catholique de Louvain in Brussels, Belgium, and colleagues examined the use of glucose as an energy source in oxygen-poor (hypoxic) and oxygen-rich areas of three tumor models in mice.
The investigators found that well-oxygenated tumor cells used lactate rather than glucose as an energy source, and the source of the lactate was the hypoxic areas of the tumor. The monocarboxylate transporter 1 (MCT1) was largely responsible for the lactate uptake, and inhibiting MCT1 led the well-oxygenated tumor cells to a switch from lactate to glucose in two mouse models of cancer. As the hypoxic tumor cells were deprived of glucose, they became sensitive to irradiation. MCT1 was expressed by a wide range of tumor types, and MCT1 was expressed only in hypoxic areas of human lung tumors, the researchers report.
"Broad MCT1 distribution among human cancers opens promising therapeutic perspectives for the development and clinical evaluation of pharmacological MCT1 inhibitors," Sonveaux and colleagues conclude.